Files
CelerisLab/tests/validation/taylor_green/shear_wave.py
T
ClaudeandClaude Opus 5.5 10069feadb test: apply shear-wave review corrections
Modal magnitude R=hypot(a,b) with amplitude error and separate phase;
free-intercept ln R rate fit with per-interval rates, log-fit residual,
t* units and finite-positive check; spurious-pressure naming with raw rms;
INVALID_CONTROL vs CONTROL_SCREEN_FAIL (refined results kept), mixed-source
check, raw ratios to both controls; docs narrow the cubic-term scope,
startup and placement limitations. oracle.py still byte-identical.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-19 00:18:20 +00:00

246 lines
10 KiB
Python

"""CPU-only oblique shear-wave reference and composite-leaf diagnostics.
Convention: integer mode MODE=(2,1) on the L x L periodic root domain, so the
wavevector k = (2*pi/L)*(2,1) points 26.565 deg from +x (mode (1,2) would be
63.435 deg). Velocity is polarized along E = (-1,2)/sqrt(5), perpendicular to k.
The frozen Taylor-Green oracle is reused for constants and geometry only.
"""
import math
import numpy as np
from oracle import CX, CY, W, U, TIMES, centers
MODE = (2, 1)
PHI = 0.0
E = np.array([-MODE[1], MODE[0]], dtype=float) / math.hypot(*MODE)
ANGLE_DEG = math.degrees(math.atan2(MODE[1], MODE[0]))
RE = 100 # Re = U L / nu, the same nu as Taylor-Green Re100 at equal N
FIT_FROM_TSTAR = 0.12 # late-time samples only; reduces startup sensitivity
INITIALIZATION = (
"physical FP64 equilibrium G at actual cell centers; rho=1 (exact p const)"
)
# Per-row screens. phase_drift_abs, residual_l2 and the run-level rate screen
# use eps(n) and are preregistered diagnostic choices, not error bounds.
LIMITS = dict(velocity_l2=0.05, spurious_pressure_scaled=0.02, mass_relative=1e-5)
# With equal absolute ceiling and floor (0.02) the comparative pressure budget
# adds no constraint unless the root control exceeds 0.01; raw ratios are kept.
FLOORS = dict(rate_error=0.002, residual_l2=0.002, spurious_pressure_scaled=0.02)
BASELINE_FACTOR = 2.0
def wavevector(length):
return 2 * np.pi / length * np.array(MODE, dtype=float)
def decay_rate(length, viscosity):
"""Exact amplitude decay rate per root step: nu |k|^2."""
k = wavevector(length)
return viscosity * float(k @ k)
def eps(n):
"""(|k| h_root)^2 with h_root = 1: dimensionless, coefficient one."""
k = wavevector(n)
return float(k @ k)
def exact(x, y, t, length, viscosity, amplitude=U):
k = wavevector(length)
a = amplitude * np.exp(-decay_rate(length, viscosity) * t)
s = np.sin(k[0] * x + k[1] * y + PHI)
p = np.zeros_like(s)
return a * E[0] * s, a * E[1] * s, p # kinematic pressure, constant
def equilibrium(rho, ux, uy):
# Same second-order D2Q9 equilibrium as oracle.initial.
cu = CX[:, None, None] * ux + CY[:, None, None] * uy
return (
W[:, None, None]
* rho
* (1 + 3 * cu + 4.5 * cu * cu - 1.5 * (ux * ux + uy * uy))
)
def initial(shape, level, length, viscosity):
x, y = centers(shape, level)
ux, uy, p = exact(x, y, 0.0, length, viscosity)
return equilibrium(1 + 3 * p, ux, uy)
def _leaves(arrays, masks):
accum = []
for level, (g, mask) in enumerate(zip(arrays, masks)):
if g.shape != (9, *mask.shape):
raise ValueError("population/mask shape mismatch")
values = g[:, mask].astype(float)
if not np.isfinite(values).all():
raise FloatingPointError("nonfinite leaf populations")
rho = values.sum(axis=0)
if (rho <= 0).any():
raise FloatingPointError("nonpositive leaf density")
x, y = centers(mask.shape, level)
area = np.full(rho.size, 0.25**level)
lev = np.full(rho.size, level)
accum.append((rho, CX @ values / rho, CY @ values / rho, x[mask], y[mask], area, lev))
return [np.concatenate(v) for v in zip(*accum)]
def metrics(arrays, masks, t, length, viscosity, initial_mass=None):
rho, ux, uy, x, y, w, lev = _leaves(arrays, masks)
volume = w.sum()
if not np.isclose(volume, length**2, rtol=0, atol=1e-10):
raise ValueError("leaf partition does not cover domain once")
k = wavevector(length)
theta = k[0] * x + k[1] * y + PHI
s, c = np.sin(theta), np.cos(theta)
v = ux * E[0] + uy * E[1]
# Weighted least squares on the actual composite quadrature (no
# continuous-orthogonality assumption).
gram = np.array([[w @ (s * s), w @ (s * c)], [w @ (s * c), w @ (c * c)]])
a_hat, b_hat = np.linalg.solve(gram, [w @ (v * s), w @ (v * c)])
ex, ey, _ = exact(x, y, t, length, viscosity)
exact_norm = w @ (ex * ex + ey * ey)
fit = a_hat * s + b_hat * c
longitudinal = (ux * k[0] + uy * k[1]) / math.sqrt(k @ k)
amplitude = U * math.exp(-decay_rate(length, viscosity) * t)
scale = amplitude * amplitude / 4 # continuum reference scale, not the TG norm
modal = math.hypot(a_hat, b_hat)
p = (rho - 1) / 3
p = p - w @ p / volume # one global gauge
mass = float(w @ rho)
return dict(
tstar=t * U / length,
mass=mass,
mass_relative=(
0.0 if initial_mass is None else abs(mass - initial_mass) / initial_mass
),
a_hat=float(a_hat),
b_hat=float(b_hat),
amplitude_exact=amplitude,
amplitude_ratio=float(a_hat / amplitude),
modal_amplitude=modal,
amplitude_error=modal / amplitude - 1,
phase_drift=float(math.atan2(b_hat, a_hat)),
phase_drift_abs=abs(float(math.atan2(b_hat, a_hat))),
velocity_l2=float(
np.sqrt(w @ ((ux - ex) ** 2 + (uy - ey) ** 2) / exact_norm)
),
residual_l2=float(
np.sqrt(w @ ((ux - fit * E[0]) ** 2 + (uy - fit * E[1]) ** 2) / exact_norm)
),
longitudinal_l2=float(np.sqrt(w @ (longitudinal**2) / exact_norm)),
spurious_pressure_rms=float(np.sqrt(w @ (p * p) / volume)),
spurious_pressure_scaled=float(np.sqrt(w @ (p * p) / volume) / scale),
spurious_pressure_max_scaled=float(np.max(np.abs(p)) / scale),
spurious_pressure_scaled_by_level=[
float(np.sqrt(w[lev == i] @ (p[lev == i] ** 2) / w[lev == i].sum()) / scale)
for i in range(len(masks))
],
rho_min=float(rho.min()),
rho_max=float(rho.max()),
max_speed=float(np.max(np.hypot(ux, uy))),
leaf_cells=int(len(rho)),
)
def fit_rate(rows, length, viscosity):
"""Free-intercept least squares of ln R, R = hypot(a_hat, b_hat), late samples.
The intercept absorbs only a constant amplitude prefactor once a single
exponential dominates; per-interval rates and the fit residual are kept so
a lingering transient stays visible. Rates are per root step of the record
(uniform 2N uses its own nu and doubled step counts).
"""
late = [r for r in rows if r["tstar"] >= FIT_FROM_TSTAR - 1e-12]
amp = np.array([math.hypot(r["a_hat"], r["b_hat"]) for r in late])
if len(late) < 3 or not (np.isfinite(amp).all() and (amp > 0).all()):
raise ValueError("need >= 3 late samples with finite positive R")
t = np.array([r["step"] for r in late], dtype=float)
(slope, intercept) = np.polyfit(t, np.log(amp), 1)
residual = np.log(amp) - (slope * t + intercept)
exact_rate = decay_rate(length, viscosity)
to_tstar = length / U # root steps per unit t*
return dict(
rate=float(-slope), exact_rate=exact_rate,
rate_tstar=float(-slope * to_tstar),
exact_rate_tstar=exact_rate * to_tstar, # = 5 (2 pi)^2 / Re
rate_error=abs(-slope / exact_rate - 1),
interval_rate_errors=[
float(-np.log(amp[i + 1] / amp[i]) / (t[i + 1] - t[i]) / exact_rate - 1)
for i in range(len(t) - 1)
],
log_fit_residual_max=float(np.max(np.abs(residual))),
)
def summarize(record):
rows = record["rows"]
n = record["n"]
out = fit_rate(rows, n, record["viscosity"])
out.update(
eps=eps(n),
complete=record["completed"] and len(rows) == len(TIMES),
residual_l2=max(r["residual_l2"] for r in rows),
phase_drift_abs=max(r["phase_drift_abs"] for r in rows),
spurious_pressure_scaled=max(r["spurious_pressure_scaled"] for r in rows),
spurious_pressure_rms=max(r["spurious_pressure_rms"] for r in rows),
amplitude_error_abs=max(abs(r["amplitude_error"]) for r in rows),
velocity_l2=max(r["velocity_l2"] for r in rows),
mass_relative=max(r["mass_relative"] for r in rows),
)
out["absolute_pass"] = out["complete"] and all(
out[key] <= out["eps"] for key in ("rate_error", "phase_drift_abs", "residual_l2")
) and all(out[key] <= limit for key, limit in LIMITS.items())
return out
def _usable(record):
try:
out = summarize(record)
except (KeyError, ValueError):
return None
finite = all(math.isfinite(v) for v in out.values() if isinstance(v, float))
return out if out["complete"] and finite else None
def assess(base_control, fine_control, refined):
"""Uniform root-spacing and finest-spacing controls versus refined runs.
INVALID_CONTROL: missing, incomplete, nonfinite or mixed-source controls.
CONTROL_SCREEN_FAIL: complete finite controls that fail a screen; refined
results are still computed and kept.
"""
if base_control is None or fine_control is None:
return dict(status="INVALID_CONTROL", reason="missing control")
n = base_control["n"]
if (base_control["depth"], fine_control["depth"], fine_control["n"]) != (1, 1, 2 * n):
raise ValueError("controls must be uniform N and uniform 2N")
if any(r["depth"] != 2 or r["n"] != n for r in refined):
raise ValueError("refined runs must be depth 2 at root N")
sources = {repr(r.get("source")) for r in [base_control, fine_control, *refined]}
base, fine = _usable(base_control), _usable(fine_control)
if base is None or fine is None or len(sources) != 1:
return dict(status="INVALID_CONTROL",
reason="incomplete/nonfinite control or mixed source")
report = dict(base_control=base, fine_control=fine, refined={}, status="PASS")
if not (base["absolute_pass"] and fine["absolute_pass"]):
report["status"] = "CONTROL_SCREEN_FAIL"
for r in refined:
s = summarize(r)
s["budget"] = {
key: max(BASELINE_FACTOR * base[key], floor) for key, floor in FLOORS.items()
}
s["budget_pass"] = all(s[key] <= s["budget"][key] for key in FLOORS)
s["control_ratios"] = {
name: {key: (s[key] / c[key] if c[key] > 0 else None)
for key in (*FLOORS, "spurious_pressure_rms")}
for name, c in (("root", base), ("finest", fine))
}
s["pass"] = s["absolute_pass"] and s["budget_pass"]
report["refined"][r["explosion"]] = s
if report["status"] == "PASS" and not s["pass"]:
report["status"] = "FAIL"
return report